Bulk-surface relationship of an electronic structure for high-throughput screening of metal oxide catalysts

摘要

Designing metal-oxides consisting of earth-abundant elements has been a crucial issue to replace precious metal catalysts. To achieve efficient screening of metal-oxide catalysts via bulk descriptors rather than surface descriptors, we investigated the relationship between the electronic structure of bulk and that of the surface for lanthanum-based perovskite oxides, LaMO3 (M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu). Through density functional theory calculations, we examined the d-band occupancy of the bulk and surface transition-metal atoms (n(Bulk) and n(surf)) and the adsorption energy of an oxygen atom (E-ads) on (001), (110), and (111) surfaces. For the (001) surface, we observed strong correlation between the n(Bulk) and n(Surf) with an R-squared value over 94%, and the result was interpreted in terms of ligand field splitting and anti-bonding/bonding level splitting. Moreover, the E-ads on the surfaces was highly correlated with the n(Bulk) with an R-squared value of more than 94%, and different surface relaxations could be explained by the bulk electronic structure (e.g., LaMnO3 vs. LaTiO3). These results suggest that a bulk-derived descriptor such as n(Bulk) can be used to screen metal-oxide catalysts. (C) 2016 Elsevier B.V. All rights reserved.